package com.cmnit.utils;

import org.apache.http.HttpEntity;
import org.apache.http.client.config.CookieSpecs;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;
import org.apache.log4j.Logger;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ConnectException;
import java.net.SocketTimeoutException;
import java.net.URL;
import java.net.URLConnection;
import java.nio.charset.StandardCharsets;

/**
 * http工具类
 *
 * @author Chan
 * @version 1.0
 * @since 2019/6/30
 */
public class HttpUtils {
    private static final Logger log = Logger.getLogger(HttpUtils.class);

    /**
     * 向指定 URL 发送POST方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是name1=value1&name2=value2的形式
     * @return 所代表远程资源的响应结果
     */
    public static String sendPost(String url, String param) {
        PrintWriter out = null;
        BufferedReader in = null;
        StringBuilder result = new StringBuilder();
        try {
            URL realUrl = new URL(url);
            // 打开和URL之间的连接
            URLConnection conn = realUrl.openConnection();
            // 设置通用的请求属性
            conn.setRequestProperty("accept", "*/*");
            conn.setRequestProperty("connection", "Keep-Alive");
            conn.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
            // 发送POST请求必须设置如下两行
            conn.setDoOutput(true);
            conn.setDoInput(true);
            // 获取URLConnection对象对应的输出流
            out = new PrintWriter(conn.getOutputStream());
            // 发送请求参数
            out.print(param);
            // flush输出流的缓冲
            out.flush();
            // 定义BufferedReader输入流来读取URL的响应
            in = new BufferedReader(new InputStreamReader(conn.getInputStream()));
            String line;
            while ((line = in.readLine()) != null) {
                result.append(line);
            }
            log.info("http返回值已获取，post请求完成");
        } catch (Exception e) {
            System.out.println("发送 POST 请求出现异常！" + e);
            e.printStackTrace();
        }
        // 使用finally块来关闭输出流、输入流
        finally {
            try {
                if (out != null) {
                    out.close();
                }
                if (in != null) {
                    in.close();
                }
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
        return result.toString();
    }

    /**
     * 发送post请求(json)
     *
     * @param url   请求地址
     * @param param 请求参数（json格式）
     * @return 响应結果
     */
    public static String doPost(String url, String param) {
        String result = null;
        try {
            // 无需传递cookies时使用，否则会出现警告“Cookie rejected”
            RequestConfig globalConfig = RequestConfig.custom().setCookieSpec(CookieSpecs.IGNORE_COOKIES).build();
            CloseableHttpClient client = HttpClients.custom().setDefaultRequestConfig(globalConfig).build();
            HttpPost httpPost = new HttpPost(url);
            httpPost.setHeader("Content-Type", "application/json;charset=UTF-8");
            StringEntity se = new StringEntity(param, StandardCharsets.UTF_8);
            se.setContentType("text/json");
            httpPost.setEntity(se);
            CloseableHttpResponse response = client.execute(httpPost);
            HttpEntity entity = response.getEntity();
            result = EntityUtils.toString(entity, "UTF-8");
        } catch (IOException e) {
            log.info("调用HttpUtils.sendPostJson ConnectException异常：" + e.getMessage());
        }
        return result;
    }

    /**
     * 向指定 URL 发送GET方法的请求
     *
     * @param url   发送请求的 URL
     * @param param 请求参数，请求参数应该是 name1=value1&name2=value2 的形式。
     * @return 所代表远程资源的响应结果
     */
    public static String doGet(String url, String param) {
        StringBuilder result = new StringBuilder();
        BufferedReader in = null;
        try {
            String urlNameString = url + "?" + param;
            log.info("sendGet - " + urlNameString);
            URL realUrl = new URL(urlNameString);
            URLConnection connection = realUrl.openConnection();
            setRequestPropertyToConnection(connection);
            connection.connect();
            in = new BufferedReader(new InputStreamReader(connection.getInputStream()));
            String line;
            while ((line = in.readLine()) != null && line.length() < 1000000) {
                result.append(line);
            }
            log.info("receiveGet - " + result);
        } catch (ConnectException e) {
            log.error("调用HttpUtils.sendGet ConnectException异常：" + e.getMessage());
        } catch (SocketTimeoutException e) {
            log.error("调用HttpUtils.sendGet SocketTimeoutException异常：" + e.getMessage());
        } catch (IOException e) {
            log.error("调用HttpUtils.sendGet IOException异常：" + e.getMessage());
        } finally {
            try {
                if (in != null) {
                    in.close();
                }
            } catch (IOException e) {
                log.error("调用in.close Exception异常：" + e.getMessage());
            }
        }
        return result.toString();
    }

    // 设置连接参数
    private static void setRequestPropertyToConnection(URLConnection connection) {
        connection.setRequestProperty("accept", "*/*");
        connection.setRequestProperty("connection", "Keep-Alive");
        connection.setRequestProperty("user-agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1;SV1)");
    }

}
